On the 200th anniversary of Charles Darwin's birth, Night Waves explores the legacies of the three titans who dominated 20th century thought - Darwin himself, Karl Marx and Sigmund Freud.
In 1950 there would have been no doubt which two were shaping the world to the greatest degree: Marx and Freud. But today Darwin is apparently the one with real purchase on our age. Or is he? Rana Mitter hosts a special programme to relive a century of intellectual competition.